Container base



FIG. 1 is a bottom left front perspective view of a container baseshowing our new design. The broken lines are for illustrative purposesonly and form no part of the claimed design;

FIG. 2 is a front elevational view thereof, the rear elevational viewbeing a mirror image;

FIG. 3 is a right side elevational view thereof, the left sideelevational view being a mirror image;

FIG. 4 is a bottom plan view thereof; and,

FIG. 5 is a top plan view thereof.

The ornamental design for a container base, as shown and described.